88pm860x_bl.c 6.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Backlight driver for Marvell Semiconductor 88PM8606
  4. *
  5. * Copyright (C) 2009 Marvell International Ltd.
  6. * Haojian Zhuang <haojian.zhuang@marvell.com>
  7. */
  8. #include <linux/init.h>
  9. #include <linux/kernel.h>
  10. #include <linux/of.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/slab.h>
  13. #include <linux/fb.h>
  14. #include <linux/i2c.h>
  15. #include <linux/backlight.h>
  16. #include <linux/mfd/88pm860x.h>
  17. #include <linux/module.h>
  18. #define MAX_BRIGHTNESS (0xFF)
  19. #define MIN_BRIGHTNESS (0)
  20. #define CURRENT_BITMASK (0x1F << 1)
  21. struct pm860x_backlight_data {
  22. struct pm860x_chip *chip;
  23. struct i2c_client *i2c;
  24. int current_brightness;
  25. int port;
  26. int pwm;
  27. int iset;
  28. int reg_duty_cycle;
  29. int reg_always_on;
  30. int reg_current;
  31. };
  32. static int backlight_power_set(struct pm860x_chip *chip, int port,
  33. int on)
  34. {
  35. int ret = -EINVAL;
  36. switch (port) {
  37. case 0:
  38. ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
  39. pm8606_osc_disable(chip, WLED1_DUTY);
  40. break;
  41. case 1:
  42. ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
  43. pm8606_osc_disable(chip, WLED2_DUTY);
  44. break;
  45. case 2:
  46. ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
  47. pm8606_osc_disable(chip, WLED3_DUTY);
  48. break;
  49. }
  50. return ret;
  51. }
  52. static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
  53. {
  54. struct pm860x_backlight_data *data = bl_get_data(bl);
  55. struct pm860x_chip *chip = data->chip;
  56. unsigned char value;
  57. int ret;
  58. if (brightness > MAX_BRIGHTNESS)
  59. value = MAX_BRIGHTNESS;
  60. else
  61. value = brightness;
  62. if (brightness)
  63. backlight_power_set(chip, data->port, 1);
  64. ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
  65. if (ret < 0)
  66. goto out;
  67. if ((data->current_brightness == 0) && brightness) {
  68. if (data->iset) {
  69. ret = pm860x_set_bits(data->i2c, data->reg_current,
  70. CURRENT_BITMASK, data->iset);
  71. if (ret < 0)
  72. goto out;
  73. }
  74. if (data->pwm) {
  75. ret = pm860x_set_bits(data->i2c, PM8606_PWM,
  76. PM8606_PWM_FREQ_MASK, data->pwm);
  77. if (ret < 0)
  78. goto out;
  79. }
  80. if (brightness == MAX_BRIGHTNESS) {
  81. /* set WLED_ON bit as 100% */
  82. ret = pm860x_set_bits(data->i2c, data->reg_always_on,
  83. PM8606_WLED_ON, PM8606_WLED_ON);
  84. }
  85. } else {
  86. if (brightness == MAX_BRIGHTNESS) {
  87. /* set WLED_ON bit as 100% */
  88. ret = pm860x_set_bits(data->i2c, data->reg_always_on,
  89. PM8606_WLED_ON, PM8606_WLED_ON);
  90. } else {
  91. /* clear WLED_ON bit since it's not 100% */
  92. ret = pm860x_set_bits(data->i2c, data->reg_always_on,
  93. PM8606_WLED_ON, 0);
  94. }
  95. }
  96. if (ret < 0)
  97. goto out;
  98. if (brightness == 0)
  99. backlight_power_set(chip, data->port, 0);
  100. dev_dbg(chip->dev, "set brightness %d\n", value);
  101. data->current_brightness = value;
  102. return 0;
  103. out:
  104. dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
  105. value, ret);
  106. return ret;
  107. }
  108. static int pm860x_backlight_update_status(struct backlight_device *bl)
  109. {
  110. return pm860x_backlight_set(bl, backlight_get_brightness(bl));
  111. }
  112. static int pm860x_backlight_get_brightness(struct backlight_device *bl)
  113. {
  114. struct pm860x_backlight_data *data = bl_get_data(bl);
  115. struct pm860x_chip *chip = data->chip;
  116. int ret;
  117. ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
  118. if (ret < 0)
  119. goto out;
  120. data->current_brightness = ret;
  121. dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
  122. return data->current_brightness;
  123. out:
  124. return -EINVAL;
  125. }
  126. static const struct backlight_ops pm860x_backlight_ops = {
  127. .options = BL_CORE_SUSPENDRESUME,
  128. .update_status = pm860x_backlight_update_status,
  129. .get_brightness = pm860x_backlight_get_brightness,
  130. };
  131. #ifdef CONFIG_OF
  132. static int pm860x_backlight_dt_init(struct platform_device *pdev,
  133. struct pm860x_backlight_data *data,
  134. char *name)
  135. {
  136. struct device_node *nproot, *np;
  137. int iset = 0;
  138. nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
  139. if (!nproot) {
  140. dev_err(&pdev->dev, "failed to find backlights node\n");
  141. return -ENODEV;
  142. }
  143. for_each_child_of_node(nproot, np) {
  144. if (of_node_name_eq(np, name)) {
  145. of_property_read_u32(np, "marvell,88pm860x-iset",
  146. &iset);
  147. data->iset = PM8606_WLED_CURRENT(iset);
  148. of_property_read_u32(np, "marvell,88pm860x-pwm",
  149. &data->pwm);
  150. of_node_put(np);
  151. break;
  152. }
  153. }
  154. of_node_put(nproot);
  155. return 0;
  156. }
  157. #else
  158. #define pm860x_backlight_dt_init(x, y, z) (-1)
  159. #endif
  160. static int pm860x_backlight_probe(struct platform_device *pdev)
  161. {
  162. struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
  163. struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
  164. struct pm860x_backlight_data *data;
  165. struct backlight_device *bl;
  166. struct resource *res;
  167. struct backlight_properties props;
  168. char name[MFD_NAME_SIZE];
  169. int ret = 0;
  170. data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
  171. GFP_KERNEL);
  172. if (data == NULL)
  173. return -ENOMEM;
  174. res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
  175. if (!res) {
  176. dev_err(&pdev->dev, "No REG resource for duty cycle\n");
  177. return -ENXIO;
  178. }
  179. data->reg_duty_cycle = res->start;
  180. res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
  181. if (!res) {
  182. dev_err(&pdev->dev, "No REG resource for always on\n");
  183. return -ENXIO;
  184. }
  185. data->reg_always_on = res->start;
  186. res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
  187. if (!res) {
  188. dev_err(&pdev->dev, "No REG resource for current\n");
  189. return -ENXIO;
  190. }
  191. data->reg_current = res->start;
  192. memset(name, 0, MFD_NAME_SIZE);
  193. sprintf(name, "backlight-%d", pdev->id);
  194. data->port = pdev->id;
  195. data->chip = chip;
  196. data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
  197. data->current_brightness = MAX_BRIGHTNESS;
  198. if (pm860x_backlight_dt_init(pdev, data, name)) {
  199. if (pdata) {
  200. data->pwm = pdata->pwm;
  201. data->iset = pdata->iset;
  202. }
  203. }
  204. memset(&props, 0, sizeof(struct backlight_properties));
  205. props.type = BACKLIGHT_RAW;
  206. props.max_brightness = MAX_BRIGHTNESS;
  207. bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
  208. &pm860x_backlight_ops, &props);
  209. if (IS_ERR(bl)) {
  210. dev_err(&pdev->dev, "failed to register backlight\n");
  211. return PTR_ERR(bl);
  212. }
  213. bl->props.brightness = MAX_BRIGHTNESS;
  214. platform_set_drvdata(pdev, bl);
  215. /* read current backlight */
  216. ret = pm860x_backlight_get_brightness(bl);
  217. if (ret < 0)
  218. return ret;
  219. backlight_update_status(bl);
  220. return 0;
  221. }
  222. static struct platform_driver pm860x_backlight_driver = {
  223. .driver = {
  224. .name = "88pm860x-backlight",
  225. },
  226. .probe = pm860x_backlight_probe,
  227. };
  228. module_platform_driver(pm860x_backlight_driver);
  229. MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
  230. MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
  231. MODULE_LICENSE("GPL");
  232. MODULE_ALIAS("platform:88pm860x-backlight");